export default{
  namespaced:true, 
  state:()=>({
     // 购物车的数组，用来存储购物车中每个商品的信息对象
        // 每个商品的信息对象，都包含如下 6 个属性：
        // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
        cart:JSON.parse(uni.getStorageSync('cart') || '[]')
        
  }),
  mutations:{
    addToCart(state,goods){
      const findResult =  state.cart.find(x=> x.goods_id ===goods.goods_id)
      
      if(!findResult){
        state.cart.push(goods)
      }else{
        findResult.goods_count++
      } 
     this.commit('m_cart/saveToStorage') 
    },
    //保存
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    //更新购物车中商品勾选状态
    updateGoodsState(state,goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
       if(findResult){
         findResult.goods_state = goods.goods_state
         this.commit('m_cart/saveToStorage') 
       }
    },
    //更新购物车商品数量
    updateGoodsCount(state,goods){
   const findResult =    state.cart.find(x => x.goods_id ===goods.goods_id)
   if(findResult){
     findResult.goods_count = goods.goods_count
     this.commit('m_cart/saveToStorage')
   }
    },
    //根据id删除购物车商品
    removeGoodsById(state,goods_id){
     state.cart = state.cart.filter(x => x.goods_id !== goods_id)
     this.commit('m_cart/saveToStorage')
    },
    //更新购物车中所有商品的勾选状态
    updateAllGoodsState(state,newState){
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
  },
  getters:{
    //购物车中所有商品的总数量
    total(state){
      // let c = 0
      // state.cart.forEach(x => c+=x.goods_count)
      // return c
    return  state.cart.reduce((total,item)=> total +=item.goods_count,0)
    },
    //购物车中已勾选商品的总数量
    checkedCount(state){
     return state.cart.filter(x => x.goods_state).reduce((total,item)=> total +=item.goods_count,0)
    },
    //已勾选商品的总价格
    checkedCountsAmount(state){
    return state.cart.filter(x => x.goods_state).reduce((total,item)=>total+=item.goods_count * item.goods_price,0).toFixed(2)
      }
  }
}